THE MEDIA BUSINESS: ADVERTISING; It's got (ho-hum) tradition on its side. Now Hershey wants to whip up some enthusiasm.

DAYS after the end of a bitter takeover battle that riveted Wall Street, Hershey Foods is drastically changing how it talks to Main Street, introducing ads asserting that it's the chocolate, stupid.

Of course, the estimated $20 million campaign for the Hershey's Milk Chocolate candy bar, in plain and almond varieties, does not use such blunt language. But the ads, which begin this week, are a significant departure for the venerable brand and the chocolate-candy category in general. Rather than wrapping the product in its usual trappings of nostalgia and Americana, Hershey is focusing single-mindedly on the pleasures of chocolate.

The desire to connect on a more emotional level with consumers 18 to 34 years old and to stand out from the campaigns for other chocolate brands is driving the shift in Hershey's strategy. Ads for chocolate brands typically play up the fun or benefits associated with snacking by featuring themes like ''break out of the ordinary,'' for Nestlé Butterfinger; ''don't let hunger happen to you,'' for Snickers; and ''gimme a break,'' for Kit Kat.

Younger consumers would nod along when they saw previous Hershey's Milk Chocolate ads with themes like ''the great American chocolate bar,'' said Chris Lansing, vice president for marketing of flagship brands at Hershey Foods in Hershey, Pa. ''Now, for the first time, they are not just nodding along but saying, 'I've got to have a Hershey bar.' ''

The timing of the campaign, coming days after the trust that controls Hershey turned down a takeover bid from the Wm. Wrigley Jr. Company and one from Nestlé and Cadbury Schweppes, is purely coincidental. But the ads, showing enthusiastic consumers delivering testimonial-style paeans to chocolate, are indicative of the steps being taken by Hershey's management to stimulate sales.

Dollar sales for the two varieties of the Hershey's Milk Chocolate bar, one of Hershey's biggest brands, totaled $258.6 million for the 52 weeks that ended Aug. 11, an increase of 5.4 percent from the period the year before, according to Information Resources, a market research company. Hershey wants its brands to avoid the malaise affecting the candy category as a whole, where annual sales growth has slowed to 2 percent or 3 percent a year, compared with earlier gains of 3 percent or 4 percent a year.

''It's time Hershey reclaimed chocolate,'' said Jonah Disend, president at Redscout in New York, a corporate-identity consulting company. ''Hershey doesn't need to use nostalgia or tell people it's iconic.''

''By reconnecting with the emotional benefits of chocolate,'' he said, ''there's actual consumer benefit in the campaign where there wasn't before. Hershey is the brand that ought to be able to own that, the way Coca-Cola owns 'refreshing.' ''

Clive Chajet, chairman at Chajet Consultancy in New York, another identity consultant, agreed. ''The more Hershey has to do with chocolate, the more effective it is as a way to contemporize the Hershey brand image,'' Mr. Chajet said.

''Hershey has the burden of constantly appealing to a new generation,'' he said, ''because the heaviest consumers of chocolate are younger. I don't think Americana or nostalgia play a large role in the lives of younger consumers.''

The new campaign was created by an agency that had not worked on the mainstay Hershey's bar before. In August, Hershey shifted the creative duties for the Hershey's Milk Chocolate bar to the New York office of DDB Worldwide, part of the Omnicom Group, from the New York office of Ogilvy & Mather Worldwide, part of the WPP Group. Both are longtime Hershey roster agencies; Ogilvy New York handles brands like Reese's Peanut Butter Cups and Reese's Pieces, while DDB New York also handles brands like Hershey's Syrup and Kit Kat.

The Hershey bar, like many icons, ''is solid, is fine, but taken for granted,'' said Gary Exelbert, the group account director at DDB New York. He added, ''When you say 'Hershey,' people say 'chocolate,' but when you say 'chocolate,' a lot of people say 'M&M's.' ''

''Who has the right more so than Hershey to be associated with chocolate?'' Mr. Exelbert asked. ''The challenge we had was, How do you make it relevant again? By reattaching Hershey to the notion of chocolate, to strike a chord with people on a deeper level.''

John Staffen, executive creative director at DDB New York, said: ''Chocolate is sexy, a magic elixir, and the Hershey bar has been devoid of that. Hershey should be the simplest, more relevant expression of chocolate to people. That's what we're trying to get back to.''

The initial television commercials show consumers of all ages, many in their 20's and 30's, standing against white backgrounds and affirming their ardor for chocolate. ''It never argues with me,'' one chocolate lover says. A man says, ''Girlfriends will leave; chocolate never will.'' A third testimonial offers the idea that Hershey's is ''the original, small squares of finite joy.'' The spots end with a new theme: ''Hershey's. Happiness.''

Plans call for print ads and posters, still being produced, to show consumers wearing T-shirts pledging their allegiance to Hershey's Milk Chocolate bars. The proposed slogans include ''available without a prescription,'' ''resistance is futile,'' ''legal in all 50 states,'' ''cheaper than a shrink'' and ''willpower is for wimps.''

The more youthful focus of the campaign is evident in the media schedule.

The commercials are to appear on shows and networks watched by younger consumers, including Comedy Central; ''Everwood,'' on WB; ''Friends'' and ''Late Night With Conan O'Brien,'' both on NBC; the Sci-Fi Channel; UPN; and VH1. The print ads are to appear in magazines like Entertainment Weekly and People.